Guide to Transplanting Broccoli

Macro shot of broccoli sprouts growing.

Broccoli is a cool-season vegetable that requires a sunny spot in the garden and well-drained soil. Transplanting vegetables such as broccoli requires a certain amount of care. The young plants are especially vulnerable when they are moved from starter pots into the ground.

Thus, when transplanting your broccoli, there are a number of things to keep in mind. Soil composition, weather conditions, and other unforeseen variables might require you to make modifications. The essential principles of transplanting broccoli include seeding indoors, hardening off, transplanting outside, and growth and maturation.

TIP: Our expert gardening advisor, Susan Patterson adds, "Plant broccoli close to fruit trees that will provide shade when the weather gets hot."

Seeding Broccoli Indoors

Many home gardeners buy vegetable starts from their local nursery. These starts were all planted indoors and given protection early on. You can forgo this step and save money by seeding yourself. You can seed directly in the ground, or you can seed indoors.

For seeding indoors, about six weeks before the last frost, start broccoli seeds in small starter pots or trays of starter cubes that resemble ice cube trays. Use lightweight potting soil and put one seed in each starter cube about ¾ inch below the surface. Keep it moist and let the seedlings grow for four weeks indoors.

Hardening Off

About 2½ weeks before the last frost, begin putting your broccoli seedlings outdoors during the day and bringing them in at night. This is called hardening off. This way they will get accustomed to being outdoors without the shock of being put in the ground immediately. Homemade broccoli starts should be hardened off for at least four days.

Transplanting Outside

After the broccoli starts have been hardened off, about two weeks before the last frost, you can put them in the ground. Before you do, keep some things in mind.

Don’t plant broccoli where any member of the Brassica family has grown during the last four growing seasons. This family includes broccoli, cauliflower, Brussels sprouts, and cabbage. The soil should be well-drained, composted, and get plenty of sun. Too much nitrogen will encourage abundant leaf growth, but it’s not ideal for the florets.

TIP: Susan suggests, "If your soil needs nitrogen, plant white clover between broccoli rows."

When the soil is ready, put the starts into the ground at least 24 inches apart from one another on all sides. Broccoli can grow from 18 inches to 3 feet in height, so it shouldn't be too close to plants it might crowd out. Bury the starts up to their first true set of leaves and water immediately.

TIP: Susan cautions, "Be very careful when transplanting broccoli not to damage the roots."

Growth and Maturation

Broccoli should always be moist but not saturated. From seed, you can expect the plants to take between 70 and 100 days to grow. Once they are in the ground, the time it takes could be anywhere from 55 to 80 days. You can fertilize the soil several weeks after transplant with an organic fertilizer.

Protect your broccoli crop from pests by using either floating row covers or an organic insecticide. Row covers are transparent white sheets of mesh that prevent the cabbage moth and cabbage fly from landing. Bacillus Thuringiensis is an organic pesticide that is mixed with water and applied to plants with a spray bottle. The cabbage worm eats the pesticide and dies soon after.

TIP: Susan recommends, "Plant thyme, onions, and nasturtiums between broccoli to help keep pests at bay."

If you take the knowledge and devote a little time each day to light maintenance and watering, you will have a plentiful broccoli crop come harvest time.